Flame retardant clear coatings for building panels

ABSTRACT

The present invention is directed to flame-retardant building panels comprising a body having a first major surface opposite a second major surface; an inorganic coating atop the first major surface, the inorganic coating being optically transparent and flame retardant and comprising a blend of a borate compound and a phosphate compound, and wherein the inorganic flame retardant coating is substantially transparent such that the first major surface of the body is visible through the inorganic coating.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/513,115, filed on May 31, 2017. The disclosure(s) of the aboveapplication(s) is (are) incorporated herein by reference.

BACKGROUND

Building products for interior room environments balance interests withrespect to cosmetic value, material cost, structural integrity, and firesafety. Previously, maximizing one or two of the aforementionedinterests required sacrificing the remaining interests. For example, abuilding panel that uses natural materials (e.g., natural grain fromreal wood, as compared to replica grain from printed wood texture) mayhave superior cosmetic value. However, such building panels alsopreviously had associated safety concerns as either the entire buildingpanel would be made from wood, thereby increasing flammability concerns,thereby endangering individuals by further fueling a fire.

Previous attempts at imparting fire repellency involved applied flameretardant compositions to the major surfaces of the cellulosicmaterials. However, such previous attempts resulted in degradation ofthe aesthetic value of the cellulosic substrate due to the flameretardant compositions interfering with the appearance of the resultingbuilding product. Thus, there is a need for building panels that can beformed from natural materials and exhibit superior cosmetic valuewithout degradation the natural aesthetic appearance imparted by suchmaterials.

BRIEF SUMMARY

The present invention is directed to a flame-retardant building panelcomprising a body having a first major surface opposite a second majorsurface, an inorganic coating atop the first major surface, theinorganic coating being optically transparent and flame retardant andcomprising a blend of a borate compound and a phosphate compound; andwherein the inorganic flame retardant coating is substantiallytransparent such that the first major surface of the body is visiblethrough the inorganic coating.

Other embodiments of the present invention include a flame-retardantbuilding panel comprising a body having a first major surface opposite asecond major surface, an inorganic coating applied to the first majorsurface, the inorganic coating formed from a composition comprising ablend of a borate compound and a phosphate compound; and wherein thecomposition has a maximum pH of 5.

In other embodiments, the present invention is directed to aflame-retardant coating composition comprising a liquid carrier, aninorganic blend comprising a borate compound and a phosphate compound,and wherein the coating composition has a maximum pH of 5 and comprisesup to about 2.5 wt. % of organic components based on the total weight ofthe coating composition.

Other embodiments of the present invention include a flame-retardantbuilding panel comprising a body having a first major surface opposite asecond major surface, a top coat comprising a first sub-layer and asecond sub-layer, the first sub-layer atop the first major surface ofthe body and the second sub-layer atop the first sub-layer, and whereinthe first sub-layer is an organic coating and the second sub-layer is aninorganic coating comprising a blend of a borate compound and aphosphate compound.

Other embodiments of the present invention include a method of forming aflame-retardant building panel comprising a) applying an inorganiccoating composition to a major surface of a body, b) drying theinorganic coating composition at an elevated temperature ranging fromabout 200° F. to about 300° F. to form a flame-retardant coating atopthe body; and wherein the inorganic coating composition comprises aliquid carrier, a borate compound and a phosphate compound, and theflame-retardant coating has a solids content of at least 99 wt. % basedon the total weight of the flame-retardant coating.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is top perspective view of the building panel according to thepresent invention;

FIG. 2 is a cross-sectional view of the building panel according to thepresent invention, the cross-sectional view being along the II line setforth in FIG. 1;

FIG. 3 is cross-sectional view of a building panel according to otherembodiments of the present invention, the cross-sectional view beingalong the II line set forth in FIG. 1;

FIG. 4 is cross-sectional view of a building panel according to otherembodiments of the present invention, the cross-sectional view beingalong the II line set forth in FIG. 1;

FIG. 5 is a ceiling system comprising the building panel of the presentinvention;

FIG. 6 is top perspective view of the building panel according toanother embodiment of the present invention;

FIG. 7 is a cross-sectional view of the building panel according to thepresent invention, the cross-sectional view being along the VII line setforth in FIG. 6; and

FIG. 8 is a ceiling system comprising the building panel of FIG. 6.

DETAILED DESCRIPTION

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

As used throughout, ranges are used as shorthand for describing each andevery value that is within the range. Any value within the range can beselected as the terminus of the range. In addition, all references citedherein are hereby incorporated by referenced in their entireties. In theevent of a conflict in a definition in the present disclosure and thatof a cited reference, the present disclosure controls.

Unless otherwise specified, all percentages and amounts expressed hereinand elsewhere in the specification should be understood to refer topercentages by weight. The amounts given are based on the active weightof the material.

The description of illustrative embodiments according to principles ofthe present invention is intended to be read in connection with theaccompanying drawings, which are to be considered part of the entirewritten description. In the description of embodiments of the inventiondisclosed herein, any reference to direction or orientation is merelyintended for convenience of description and is not intended in any wayto limit the scope of the present invention. Relative terms such as“lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,”“down,” “top,” and “bottom” as well as derivatives thereof (e.g.,“horizontally,” “downwardly,” “upwardly,” etc.) should be construed torefer to the orientation as then described or as shown in the drawingunder discussion. These relative terms are for convenience ofdescription only and do not require that the apparatus be constructed oroperated in a particular orientation unless explicitly indicated assuch.

Terms such as “attached,” “affixed,” “connected,” “coupled,”“interconnected,” and similar refer to a relationship wherein structuresare secured or attached to one another either directly or indirectlythrough intervening structures, as well as both movable or rigidattachments or relationships, unless expressly described otherwise.Moreover, the features and benefits of the invention are illustrated byreference to the exemplified embodiments. Accordingly, the inventionexpressly should not be limited to such exemplary embodimentsillustrating some possible non-limiting combination of features that mayexist alone or in other combinations of features; the scope of theinvention being defined by the claims appended hereto.

Unless otherwise specified, all percentages and amounts expressed hereinand elsewhere in the specification should be understood to refer topercentages by weight. The amounts given are based on the active weightof the material. According to the present application, the term “about”means+/−5% of the reference value. According to the present application,the term “substantially free” less than about 0.1 wt. % based on thetotal of the referenced value.

Referring to FIGS. 1 and 5, the present invention includes a ceilingsystem 1 as well as a building panel 10 that may be used in the ceilingsystem 1. The ceiling system 1 may comprise at least one or more of thebuilding panels 10 installed in an interior space, whereby the interiorspace comprises a plenum space 3 and an active room environment 2. Theplenum space 3 is defined by the space occupied between a structuralbarrier 4 between floors of a building and the lower major surface 12 ofthe building panel 10. The plenum space 3 provides space for mechanicallines within a building (e.g., HVAC, electrical lines, plumbing,telecommunications, etc.). The active space 2 is defined by the spaceoccupied beneath the upper major surface 11 of the building panel 10 forone floor in the building. The active space 2 provides room for thebuilding occupants during normal intended use of the building (e.g., inan office building, the active space would be occupied by officescontaining computers, lamps, etc.).

Each of the building panels 10 may be supported in the interior space byone or more supports 5. Each of the building panels 10 are installedsuch that the upper major surface 11 of the building panel 10 faces theactive room environment 2 and the lower major surface 12 of the buildingpanel 10 faces the plenum space 3. The building panels 10 of the presentinvention have superior fire safety performance—particularly when a fireoriginates in the active room environment 2—without sacrificing thedesired aesthetic appearance of the building panel 10, as discussedherein.

Referring to FIG. 1, the present invention is a building panel 10 havingan upper major surface 11, a lower major surface 12 that is opposite theupper major surface 11, and major side surfaces 13 that extend from theupper major surface 11 to the lower major surface 12 to form a perimeterof the building panel 10. The major side surfaces 13 may comprise firstand second longitudinal side surfaces 41, 42 extending substantiallyparallel to each other. The major side surfaces 13 may further comprisefirst and second transverse side surfaces 31, 32 extending substantiallyparallel to each other. The first and second longitudinal side surfaces41, 42 may extend substantially orthogonal to the first and secondtransverse side surfaces 31, 32.

The building panel 10 may have a panel thickness “t_(P)” as measuredfrom the upper major surface 11 to the lower major surface 12. The panelthickness t_(P) may range from about 25 mils to about 3,000mils—including all values and sub-ranges there-between. In someembodiments, the panel thickness t_(P) may range from about 25 mils toabout 600 mils—including all values and sub-ranges there-between. Insome embodiments, the panel thickness t_(P) may range from about 700mils to about 2,000 mils—including all values and sub-rangesthere-between.

The building panel 10 may have a panel length “L_(P)” as measured fromthe first transverse side surface 31 to the second transverse sidesurface 32—i.e., the distance along one of the first or secondlongitudinal side surfaces 41, 42. The panel length L_(P) may range fromabout 6 inches to about 100 inches—including all values and sub-rangesthere-between. The building panel 10 may have a panel width “W_(P)” asmeasured from the first longitudinal side surface 41 to the secondlongitudinal side surface 42—i.e., the distance along one of the firstor second transverse side surfaces 31, 32. The panel width W_(P) mayrange from about 2 inches to about 60 inches—including all values andsub-ranges there-between. In some embodiments, the panel width W_(P) mayrange from about 12 inches to about 60 inches—including all values andsub-ranges there-between.

The building panel 10 of the present invention comprises a body 100having a coating 500 applied thereto. The body 100 may comprise a firstmajor surface 111 opposite a second major surface 112 and a side surface113 extending there-between. The body 100 may be formed from acellulosic material (e.g., wood), metal, organic polymer, inorganicpolymer, and combinations thereof. The body 100 may be formed from asingle layer of material (also referred to as an integral structure) orthe body 100 may have a laminate structure formed from at least twolayers. As discussed in greater detail herein, the body 100 having alaminate structure may comprise one or more layers of a cellulosic layer400, a substrate layer 200, and/or an adhesive layer 300. Although notpictured, the coating 500 of the present invention may be applied to anon-woven scrim. Non-limiting examples of non-woven scrim includefiberglass non-woven scrims. The non-woven scrim may form at least oneof the first or second major surface 11, 12 of the building panel 10.

The building panel 10 may comprise a decorative pattern 30 that isvisible from the upper major surface 11, the lower major surface 12,and/or the major side surface 13. The decorative pattern 30 may comprisea pattern formed from natural materials, such as cellulosic materials(e.g., wood grain, knots, burl, etc.) or synthetic materials, such as aprinted ink. The decorative pattern 30 may be a body decorative patternthat exists on one of the first major surface 111, second major surface112, or side surface 113 of the body 100, whereby the body decorativepattern is visible through the coating 500.

The coating 500 may be independently applied to each of the first majorsurface 111, the second major surface 112, and/or the side surface 113of the body 100. In a preferred embodiment, the coating 500 is appliedto the first major surface 111 of the body 100—as shown in FIG. 2. Inanother preferred embodiment, the coating 1500 may be applied to each ofthe first major surface 1111, the second major surface 1112, and theside surface 1113 of the body 1100 such that the coating 1500encapsulates the body 100—as shown in FIGS. 6 and 7.

The coating 500 may be clear or substantially clear. For the purposes ofthis application, the phrases “substantially clear” or “substantiallytransparent” refers to materials that have the property of transmittinglight in such a way that a normal, human eye (i.e., one belonging to aperson with so-called “20/20” vision) or a suitable viewing device cansee through the material distinctly. The level of transparency shouldgenerally be one which permits a normal, human eye to distinguishobjects having length and width on the order of at least 0.5 inches, andshould not significantly distort the perceived color of the originalobject. The coating 500 should be substantially clear (or substantiallytransparent) such that the underlying body decorative feature can bevisible from the upper major surface 11 of the building panel 10 as thedecorative pattern 30 on the overall building panel 10, as discussedfurther herein. The term “substantially clear” or “substantiallytransparent” may also refer to the coating having at least 70% opticalclarity, whereby 100% optical clarity refers to an underlying surfacebeing completely unhindered visually by the coating 500.

Referring now to FIG. 2, the coating 500 may comprises an upper coatingsurface 511 opposite a lower coating surface 512. The coating 500 maycomprise a coating side surface 513 that extends from the upper coatingsurface 511 to the lower coating surface 512 and forms a perimeter ofthe coating 500. The coating side surface 513 may form a portion of themajor side surface 13 of the building panel 10. Stated otherwise, themajor side surface 13 of the building panel 10 may comprise the coatingside surface 513. The coating 500 may have a coating thickness “t_(C)”ranging from about 0.5 mils to about 3.0 mils—including all values andsub-ranges there-between—as measured from the upper coating surface 511to the lower coating surface 512.

The coating 500 may comprise an inorganic composition that issubstantially clear. According to the present invention, the phrase“inorganic composition” refers to a dry-state composition having lessthan 3 wt. % of organic compounds present based on the total dry-weightof the referenced inorganic composition, preferably less than 1.5 wt. %of organic compounds present based on the total dry-weight of thereferenced inorganic composition. According to the present invention,the phrase “inorganic composition” may also refer to a wet-statecomposition that has less than 5.0 wt. % of organic compounds presentbased on the total wet-weight of the referenced inorganic composition,preferably less than 3.0 wt. % of organic compounds present based on thetotal wet-weight of the referenced inorganic composition.

The phrase “dry-weight” refers to the weight of a referenced componentor composition without the weight of any carrier. Thus, when calculatingthe amounts of components based on dry-weight, the calculation are to bebased solely on the solid components (e.g., binder, filler, hydrophobiccomponent, fibers, etc.) and should exclude any amount of residualcarrier (e.g., water, VOC solvent) that may still be present from awet-state, which will be discussed further herein. Additionally,according to the present invention, the phrase “dry-state” refers to acomponent or composition that is substantially free of carrier, ascompared to the phrase “wet-state,” which refers to that component stillcontaining various amounts of carrier. The term “weight-state” refers toa component or composition that further comprises a carrier. Similarly,the phrase “wet-weight” refers to a total weight of component orcomposition that includes the weight of the carrier when in thewet-state.

The inorganic composition may be a glass-forming composition. Accordingto the present invention, a “glass-forming composition” comprises afirst glass component and a second glass component that together reactto form an inorganic glass-like surface when exposed to elevatedtemperatures—such as elevated temperatures during a fire. The inorganiccomposition of the present invention exhibits a pH ranging from about1.5 to about 5—including all pHs and sub-ranges there-between. In apreferred embodiment, the pH ranges from about 1.7 to about 4—includingall pHs and sub-ranges there-between. In a preferred embodiment, the pHis less than about 3.

The first glass component comprises a phosphate compound. The secondglass component comprises a borate compound. The first glass componentand the second glass component may be present in a weight ratio rangingfrom about 5:1 to about 80:1—including all ratios and sub-rangesthere-between.

The first glass component may be present in an amount ranging from about40.0 wt. % to about 80.0 wt. %—including all wt. % and sub-rangesthere-between—based on the total weight of the inorganic composition inthe dry-state. In a preferred embodiment, the first glass component maybe present in an amount ranging from about 55.0 wt. % to about 75.0 wt.%—including all wt. % and sub-ranges there-between—based on the totalweight of the inorganic composition in the dry-state. The second glasscomponent may be present in an amount ranging from about 0.5 wt. % toabout 15.0 wt. %—including all wt. % and sub-ranges there-between—basedon the total weight of the inorganic composition in the dry-state. In apreferred embodiment, the second glass component may be present in anamount ranging from about 1.0 wt. % to about 10.5 wt. %—including allwt. % and sub-ranges there-between—based on the total weight of theinorganic composition in the dry-state.

Non-limiting examples of the phosphate compound of the first glasscomponent include phosphoric acid (H₃PO₄), pyrophosphoric acid (H₄P₂O₇),polyphosphoric acid, sodium phosphate, potassium phosphate, aluminumtris (dihydrogen phosphate), other phosphate-ion forming compounds, andcombinations thereof. Non-limiting examples of the borate compound ofthe second glass component include boron trioxide (B₂O₃), zinc borate,and other soluble borate forming compound at pH between 1 and 5, andcombinations thereof. Several variants of zinc borate exist and includeZinc borate Firebrake ZB (2ZnO.3B₂O₃.3.5H₂O), Zinc borate Firebrake 500(2ZnO.3B₂O₃), Zinc borate Firebrake 415 (4ZnO—B₂O₃. H₂O), ZB-467(4ZnO.6B₂O₃.7H₂O), and ZB-223 (2ZnO-2B₂O₃.3H₂O). According to someembodiments the zinc borate may also serve as a fungicide.

Upon exposure to elevated temperatures, the first and second glasscompositions react to form a phosphoborate glass layer (also referred toas the “glass layer”). The glass layer forms a hard protective andheat-insulative barrier that is especially helpful in preventing thebody 100 from igniting at elevated temperatures, for example when thebody 100 is formed from a cellulosic material as discussed furtherherein. The heat-insulative barrier formed by the coating 500 isespecially useful when the upper major surface 11, lower major surface12, and/or side surface 13 of the building panel 10 is exposed to heatfrom a fire that exists in the active room environment 2 of the ceilingsystem 1 (as shown in FIG. 5). The heat-insulative barrier created bythe inorganic composition slows and prevents further propagation of heatand flame through the coating 500 and, therefore, through the rest ofthe body 100 of the building panel 10.

The inorganic composition may optionally comprise other additives orfillers such as, but not limited to fire retarding compounds (alsoreferred to as “flame retardant”), adhesion promoters, viscositymodifying agents, wetting agents, catalyst, cross-linkers, andultra-violet stabilizers. According to some embodiments, the inorganiccomposition may further comprise organic compounds so long as theoverall inorganic composition includes less than 5 wt. % of organiccompounds in the overall inorganic composition. According to someembodiments, the inorganic composition may be substantially free ofblowing-agent. The wetting agent may be present in a non-zero amountthat is less than about 0.1 wt. %—based on the total dry-weight of theinorganic composition.

The filler may be present in the inorganic coating in an amount rangingfrom about 15 wt. % to about 75 wt. %—including all amounts andsub-range there-between—based on the total dry weight of the inorganiccoating. Non-limiting examples of filler may include calcium carbonate(CaCO₃), aluminum carbonate (Al₂(CO₃)₃), lithium carbonate (LiCO₃),magnesium carbonate (MgCO₃), fumed silica, aluminum oxide (Al₂O₃), andcombinations thereof.

The flame retardants may be present in the coating 500 in an amountranging from about 0 wt. % to about 50 wt. %—including all values andsub-ranges there-between—based on the total weight of the coating 500.Non-limiting examples of flame retardant may include ammonium hydroxide,magnesium hydroxide, huntite, hydromagnesite, silica, polyphosphate,chloride salts—such as sodium chloride, antimony oxide, and borates,such as calcium borate, magnesium borate, zinc borate, and combinationsthereof.

A non-limiting example of viscosity modifying agent may includehydroxyethyl cellulose, bentonite, polyacrylic rheology modifier,polyurethane rheology modifier, silica, and combination thereof.Hydroxyethyl cellulose is an organic compound—therefore, thehydroxyethyl cellulose may be present in the inorganic composition in anamount that ranges from a non-zero amount to less than 5 wt. % based onthe total dry-weight of the inorganic composition. In a preferredembodiment, the hydroxyethyl cellulose may be present in the inorganiccomposition in an amount that ranges from a non-zero amount to less than3 wt. % based on the total dry-weight of the inorganic composition.

The inorganic composition may further comprise a cross-linker thatfacilitates curing of the coating at lower temperatures. Non-limitingexample of cross-linker include triethanolamine, polyol, amine orpolyamine, as well as other suitable crosslinker that do not inhibitfilm formation of the coating. In a preferred embodiment, thecrosslinker comprises triethanolamine, which is an organic compound.Therefore, the triethanolamine may be present in the inorganiccomposition in an amount that ranges from a non-zero amount to less than5 wt. % based on the total wet-weight of the inorganic composition(i.e., before cross-linking). In a preferred embodiment, thetriethanolamine may be present in the inorganic composition such thatthe total organic content ranges from a non-zero amount to less than 3wt. % based on the total wet-weight of the inorganic composition.

According to the present invention, the coating 500 may be comprised ofa single integral layer (FIG. 2) or a plurality of sub-layers 540, 550,560 (FIGS. 3 and 4). The coating 500 show in FIG. 2 having a singleintegral layer comprises the inorganic composition of the presentinvention.

Referring now to FIG. 3, the coating 500 of the present invention maycomprise may comprise a first sub-layer 540 and a second sub-layer 550,whereby the first sub-layer 540 is directly atop one or more of thefirst major surface 111, second major surface 112, and/or side surface113 of the body 100. The second sub-layer 550 may be directly atop thefirst sub-layer 540. The second sub-layer 550 comprises the inorganiccomposition of the present invention. In such embodiments, the inorganiccomposition may be present in an amount ranging from about 95 wt. % toabout 100 wt. %—including all values and sub-ranges there-between—basedon the total dry-weight of the second sub-layer 550.

Referring now to FIG. 4, the coating 500 of the present invention maycomprise may comprise a first sub-layer 540, a second sub-layer 550, anda third sub-layer 560, whereby the first sub-layer 540 is directly atopone or more of the first major surface 111, second major surface 112,and/or side surface 113 of the body 100. The second sub-layer 550 may bedirectly atop the first sub-layer 540, and the third sub-layer 560 maybe directly atop the second sub-layer 550. The second sub-layer 550 maycomprise the inorganic composition of the present invention. In suchembodiments, the inorganic composition may be present in an amountranging from about 95 wt. % to about 100 wt. %—including all values andsub-ranges there-between—based on the total dry-weight of the secondsub-layer 550.

According to the present invention, the first sub-layer 540 may also bereferred to as a “base coating.” The first sub-layer 540 may be anorganic coating. According to the present invention, the term “organiccoating” refers to a coating in the dry-state that comprises at least 10wt. % of organic compounds based on the total weight of the referencedorganic coating in the dry-state, preferably at least 15 wt. % oforganic compounds based on the total weight of the referenced organiccoating in the dry-state.

The first sub-layer 540 may comprise a polymer binder in an amountranging from about 70 wt. % to about 95 wt. %—including all values andsub-ranges there-between—based on the total dry-weight of the firstsub-layer 540.

The polymer binder may comprise polymer produced from unsaturatedmonomers.

Specifically, the polymer may be a homopolymer or copolymer producedfrom ethylenically unsaturated monomers, such as styrene,alpha-methylstyrene, polymethylsiloxane, vinyl toluene, ethylene,propylene, vinyl acetate, vinyl chloride, vinylidene chloride,acrylonitrile, acrylamide, methacrylamide, acid, methacrylic acid,(meth)acryloxy-propionic acid, conic acid, aconitic acid, maleic acid,monomethyl maleate, monomethyl fumarate, monomethyl itaconate, various(C₁-C₂₀) alkyl or (C₃-C₂₀) alkenyl esters of (meth)acrylic acid, variouslacquers, latex-based binders and the like. The expression(meth)acrylic, as used herein, is intended to serve as a genericexpression embracing both acrylic and methacrylic acid and estersthereof e.g., methyl (meth)acrylate, ethyl (meth)acrylate, butyl(meth)acrylate, isohutyl (meth)acrylate, 2-ethyl hexyl(meth)acrylate,benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate,palmityl (meth)acrylate, stearyl (meth)acrylate and the like. In otherembodiments, the coating polymer binder may include polymer comprisingpolyurethane, polyester, polyester-modified polyurethane, or acombination thereof.

The polymer binder of the first sub-layer 540 may have a glasstransition temperature Tg ranging from about 10° F. to about 115°F.—including all values and sub-ranges there-between.

The first sub-layer 540 may further comprise one or more nonionicsurfactants in the amount of 0.1 wt. % to about 1.0 wt. %—based on thetotal dry-weight of the first sub-layer 540—including all amount andsub-ranges there-between. The nonionic surfactant component can be asingle surfactant or a mixture of two or more nonionic surfactants, themixture having appropriate HLB values. Suitable nonionic surfactantsinclude but are not limited to ethoxylated nonylphenols, ethoxylatedalcohols, ethoxylated castor oil, polyethylene glycol fatty acid esters,and ethyleneglycol-propyleneglycol copolymers. The contemplated nonionicsurfactants include ethoxylated nonylphenols and polyethylene glycolfatty acid esters.

The second sub-layer 550 may be an inorganic coating that comprises theinorganic glass-forming composition of the present invention. The secondsub-layer 550 may be a combination of multiple coatings of the inorganicglass-forming composition. The second sub-layer 550 may be substantiallyclear. According to the present invention, the phrase “inorganiccoating” refers to the coating having less than 5 wt. % of organiccompounds present based on the total dry weight of the referencedinorganic coating, preferably less than 3 wt. % of organic compoundspresent based on the total weight of the referenced inorganic coating inthe dry-state. According to some embodiments, the inorganic coating ofthe second sub-layer 550 may be formed entirely from the inorganiccomposition of the present invention.

The third sub-layer 560 may be referred to as “topcoat.” The thirdsub-layer 560 may be an inorganic coating according to the presentinvention or an organic coating. The third sub-layer 560 may comprise asealant composition. The sealant composition may comprise a sealantpolymer binder and a flame retardant. Referring now to FIG. 4, otherembodiments provide that the coating 500 may further comprise a thirdsub-layer 560 atop the second sub-layer 550, which is atop the firstsub-layer 540 that is atop the cellulosic layer 400. The third sub-layer560 may be formed from a moisture barrier composition that impartsmoisture barrier properties to the resulting third sub-layer 560. Themoisture barrier composition may be comprised of hydrophobic polymericbinder, which may or may not be cross-linked, as well as variousadditives and fillers.

The sealant polymer binder may be present in an amount ranging fromabout 10 wt. % to about 100 wt. %—including all values and sub-rangesthere-between—based on the total weight of the sealant composition inthe dry-state. The flame retardant may be present in thecellulosic-layer sealant composition in an amount ranging from about 0wt. % to about 50 wt. %—including all values and sub-rangesthere-between—based on the total dry-weight of the cellulosic-layersealant composition.

The sealant polymer binder may comprise one or more vinyl or acrylichomopolymers or copolymers formed from ethylenically unsaturatedmonomers such as ethylene or butadiene and vinyl monomers such asstyrene, vinyl esters such as vinyl acetate, vinyl propionate, vinylbutyrates, acrylic acid, methacrylic acid, or esters of acrylic acidand/or esters of methacrylic acid. The esters of acrylic or methacrylicacid may have an alkyl ester portion containing 1 to 12 carbon atoms aswell as aromatic derivatives of acrylic and methacrylic acid, and caninclude, for example, acrylic and methacrylic acid, methyl acrylate andmethyl methacrylate, ethyl acrylate and ethyl methacrylate, butylacrylate and butyl methacrylate, propyl acrylate and propylmethacrylate, 2-ethyl hexyl acrylate and 2-ethyl hexyl methacrylate,cyclohexyl acrylate and cyclohexyl methacrylate, decyl acrylate anddecyl methacrylate, isodecyl acrylate and isodecyl methacrylate, benzylacrylate and benzyl methacrylate and various reaction products such asbutyl, phenyl, and cresyl glycidyl ethers reacted with acrylic andmethacrylic acids, preferred embodiment, the sealant binder comprises aself-crosslinking acrylic binder. Non-limiting examples of hydrophobicpolymeric binder produced from unsaturated monomers. Specifically, thehydrophobic polymer may be a homopolymer or copolymer produced fromethylenically unsaturated monomers, such as styrene,alpha-methylstyrene, vinyl toluene, ethylene, propylene, vinyl acetate,vinyl chloride, vinylidene chloride, acrylonitrile, acrylamide,methacrylamide, acrylic acid, methacrylic acid, (meth)acryloxy-propionicacid, itaconic acid, aconitic acid, maleic acid, monomethyl maleate,monomethyl fumarate, monomethyl itaconate, various (C₁-C₂₀) alkyl or(C₃-C₂₀) alkenyl esters of (meth)acrylic acid and the like. Theexpression (meth)acrylic, as used herein, is intended to serve as ageneric expression embracing both acrylic and methacrylic acid andesters thereof e.g., methyl (meth)acrylate, ethyl (meth)acrylate, butyl(meth)acrylate, isobutyl (meth)acrylate, 2-ethyl hexyl(meth)acrylate,benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate,palmityl (meth)acrylate, stearyl (meth)acrylate and the like. In otherembodiments, the hydrophobic polymeric binder may include polymercomprising polyurethane, polyester, polyester-modified polyurethane,epoxy or a combination thereof.

The hydrophobic polymer may be present in an amount ranging from about70 wt. % to about 100 wt. %—including all values and sub-rangesthere-between—based on the total weight of the moisture barriercomposition.

The flame retardant of the first sub-layer 540 may include ammoniumhydroxide, magnesium hydroxide, huntite, hydromagnesite, silica,polyphosphate, melamine cyanurate, chloride salts—such as sodiumchloride, antimony oxide, and borates, such as calcium borate, magnesiumborate, zinc borate, and combinations thereof.

Generally, the coating 500 may be applied directly to one of the firstmajor surface 111, second major surface 112, and/or side surface 113 ofthe body 100, optionally with the addition of a carrier such as water.The coating 500—including each sub-layer 540, 550, 560—may be applied byspray, roll-coating, dip coating, curtain coating, brushing, bladecoating, or the like, followed by drying and/or curing (optionally withthe addition of heat) for a period of time to form the coating 500 atopthe cellulosic layer 400—as discussed in greater detail herein.

The first sub-layer 540 may be applied in the wet-state directly to atleast one of the first major surface 111, second major surface 112,and/or side surface 113 of the body 100. In the wet-state, the firstsub-layer 540 may comprise a carrier in an amount ranging from about 35wt. % to about 55 wt. %—including all values and sub-rangesthere-between—based on the total weight of the wet-state first sub-layer540. In the wet-state, the first sub-layer 540 may be applied in anamount such that the first sub-layer 540 has a wet thickness rangingfrom about 0.5 mils to about 2.5 mils—including all values andsub-ranges there-between. The carrier may be selected from water, anorganic solvent, or a combination thereof. In a preferred embodiment,the wet-state sealant composition is a waterborne system having acarrier of water and a low VOC (i.e., volatile organic compound)content—i.e. substantially free of VOC solvents. The first sub-layer 540in the wet-state may then be cured or dried (optionally with theaddition of heat) for a first time period, thereby forming the firstsub-layer 540 atop the body 100.

The resulting first sub-layer 540 may comprise a first sub-layer uppersurface 541 and a first sub-layer lower surface 542 opposite the firstsub-layer upper surface 541. The first sub-layer 540 may have a firstsub-layer thickness “t_(C1)” as measured from the first sub-layer uppersurface 541 to the first sub-layer lower surface 542. The firstsub-layer thickness t_(C1) may range from 0.1 mils to 1.0 mils—includingall values and sub-ranges there-between. The first sub-layer 540 maycomprise a first sub-layer side surface 543 that extends from the firstsub-layer upper surface 541 to the first sub-layer lower surface 542 andforms a perimeter of the first sub-layer 540.

As previously discussed, the body 100 may be formed from a cellulosicmaterial, which comprises pores. Thus, once the first sub-layer 540 isapplied to one of the first major surface 111, second major surface 112,and/or side surface 113 of the body 100, at least a portion of the firstsub-layer 540 may penetrate into and seal the pores in a directextending from one of the first major surface 111, second major surface112, and/or side surface 113 of the body 100 toward the center of thebody 100. The first sub-layer 540 in the wet-state may then be dried,optionally, at an elevated temperature, thereby rendering the firstsub-layer 540 in the dry state.

The second sub-layer 550 may be formed by directly applying thepreviously discussed inorganic composition in the wet-state to the firstsub-layer upper surface 541 of the first sub-layer 540. In thewet-state, the second sub-layer 550 may be applied in an amount suchthat the second sub-layer 550 has a wet thickness ranging from about 0.1mils to about 1.0 mils—including all values and sub-rangesthere-between.

The inorganic composition may then be dried (optionally with theaddition of heat) for a second time period of time, thereby forming thesecond sub-layer 550 atop the first sub-layer 540. The resulting secondsub-layer 550 may comprise a second sub-layer upper surface 551 and asecond sub-layer lower surface 552 opposite the second sub-layer uppersurface 551. The second sub-layer 550 in the wet-state may be dried at atemperature ranging from about 190° F. to about 300° F.—including alltemperatures and sub-ranges there-between. In a preferred embodiment,the second sub-layer 550 in the wet-state may be dried at a temperatureranging from about 200° F. to about 290° F.—including all temperaturesand sub-ranges there-between.

The second sub-layer 550 may have a second sub-layer thickness “t_(C2).”as measured from the second sub-layer upper surface 551 to the secondsub-layer lower surface 552. The second sub-layer thickness t_(C2) mayrange from about 0.02 mils to about 0.7 mils. The second sub-layer 550may comprise a second sub-layer side surface 553 that extends from thesecond sub-layer upper surface 551 to the second sub-layer lower surface552 and forms a perimeter of the second sub-layer 550.

The first sub-layer side surface 543 and the second sub-layer sidesurface 553 may form at least a portion of the coating side surface 513.Stated otherwise, the coating side surface 513 may comprise the firstsub-layer side surface 543 and the second sub-layer side surface 553.The overall coating thickness t_(C) of coating 500 may be the summationof the first sub-layer thickness t_(C1) and the second sub-layerthickness t_(C2)—as follows:

t _(C) =t _(C1) +t _(C2)

According to these embodiments, the first sub-layer lower surface 542 ofthe first sub-layer 540 may contact the upper cellulosic surface 411 ofthe cellulosic layer 400. The first sub-layer upper surface 541 maycontact the second sub-layer lower surface 552 of the second sub-layer550. The second sub-layer upper surface 551 may form at least part ofthe upper coating surface 511 of the coating 500. The first sub-layerlower surface 542 may form at least part of the lower coating surface512 of the coating 500. The second sub-layer upper surface 551 may format least part of the upper major surface 11 of the building panel 10.

The first sub-layer 540 may form a physical barrier that at leastpartially separates the body 100 from the second sub-layer 550. Thephysical barrier formed by the first sub-layer 540 may prevent at leastsome of the second sub-layer 550 (which comprises the glass-formingcomposition) from penetrating into the body 100 (e.g., a cellulosic body100 having porous surfaces). According to some embodiments, thephosphoborate glass heat-insulative barrier that is created byglass-forming composition of the second sub-layer 540 may be separatedfrom at least one of the first major surface 111, second major surface112, and/or side surface 113 of the body 100 by a distance equal to thefirst sub-layer thickness t_(C1).

The third sub-layer 560 may be formed by applying the moisture barriercomposition with the addition of one or more organic solvents.Non-limiting examples of organic solvents include toluene, ethanol,acetone, butyl acetate, methyl ethyl ketone, ethyl 3-ethoxypropionate.The barrier composition may be present relative to the organic solventin a weight ratio ranging from about 5:1 to about 1:20. Afterapplication to the second sub-layer upper surface 551, the moisturebarrier composition may be dried for a third period of time, optionallyat an elevated temperature, sufficient to drive off any organic solvent.The resulting third sub-layer 560 may be a continuous or discontinuouscoating having an third sub-layer upper surface 561 and a thirdsub-layer lower surface 562 opposite the third sub-layer upper surface561.

In the wet-state, the third sub-layer 560 may be applied in an amountsuch that the third sub-layer 560 has a wet thickness ranging from about1.0 mils to about 10.0 mils—including all values and sub-rangesthere-between. After drying, the third sub-layer 560 in the dry-statemay have a third sub-layer thickness “t_(C3)” as measured from the thirdsub-layer upper surface 561 to the third sub-layer lower surface 562.The third sub-layer thickness t_(C3) may range from about 1 mils toabout 6 mils. The third sub-layer 560 may comprise a third sub-layerside surface 563 that extends from the third sub-layer upper surface 561to the third sub-layer lower surface 562 and forms a perimeter of thesecond sub-layer 560.

According to such embodiments, the overall coating thickness t_(C) ofcoating 500 may be the summation of the first sub-layer thicknesst_(C1), the second sub-layer thickness t_(C2), and the third sub-layerthickness t_(C3)—as follows:

t _(C) =t _(C1) +t _(C2) +t _(C3)

According to these other embodiments, the first sub-layer lower surface542 of the first sub-layer 540 may contact the upper cellulosic surface411 of the cellulosic layer 400. The first sub-layer upper surface 541may contact the second sub-layer lower surface 552 of the secondsub-layer 550. The second sub-layer upper surface 551 may contact thethird sub-layer lower surface 562 of the second sub-layer 560. The thirdsub-layer upper surface 561 may form at least part of the upper coating511 of the coating 500. The first sub-layer lower surface 542 may format least part of the lower coating surface 512 of the coating 500. Thethird sub-layer upper surface 561 may form at least part of the uppermajor surface 11 of the building panel 10.

According to other embodiments, the coating 500 may comprise only thesecond sub-layer 550 and the third sub-layer 560 without the firstsub-layer 540 (not pictured). In such embodiments, the second sub-layer550 may be directly atop one of the first major surface 111, secondmajor surface 112, and/or side surface 113 of the body 100 and the thirdsub-layer 560 may be directly atop the second sub-layer upper surface551 of the second sub-layer 550. In such embodiments, the secondsub-layer 550 acts as a sealant and is capable of sealing the one of thefirst major surface 111, second major surface 112, and/or side surface113 of the body 100, while simultaneously acting as an insulativebarrier created from the glass-forming composition of the inorganiccomposition.

According to other embodiments, the coating 500 may comprise only thesecond sub-layer 550. In such embodiments, the second sub-layer 550 actsas a sealant and is capable of sealing one of the first major surface111, second major surface 112, and/or side surface 113 of the body 100,while simultaneously acting as a insulative barrier created from theglass-forming composition of the inorganic composition, in situationswhere moisture resistance of the coating is not required.

Referring now to FIGS. 2-4, the body 100 may comprise a cellulosic layer400, whereby the coating 500 is applied directly to the cellulosic layer400 of the body 100. In other embodiments where the body 100 may be alaminate structure comprising multiple layers that includes a cellulosiclayer 400 atop a substrate layer 200 with an adhesive layer 300positioned there-between. The body 100 may also comprise the substratelayer 200 without the cellulosic layer 400 or adhesive layer 200,whereby the coating 500 is applied to at least one surface of thesubstrate layer 200—as discussed further herein.

Referring to FIG. 2, the cellulosic layer 400 may comprise an uppercellulosic surface 411 and a lower cellulosic surface 412 opposite theupper cellulosic surface 411. The cellulosic layer 400 may comprise acellulosic side surface 413 that extends from the upper cellulosicsurface 411 to the lower cellulosic surface 412 and forms a perimeter ofthe cellulosic layer 400. The cellulosic side surface 413 may form aportion of the side surface 113 of the body 100. Stated otherwise, theside surface 113 of the body 100 may comprise the cellulosic sidesurface 413. The side surface 113 of the body 100 may form a major sidesurface 13 of the building panel 10. The first major surface 111 of thebody 100 may comprise the upper cellulosic surface 411.

The cellulosic layer 400 may have a cellulosic layer thickness “t_(CL)”as measured by the distance between the upper and lower cellulosicsurfaces 411, 412. The cellulosic layer thickness t_(CL) may range fromabout 10 mils to about 3,000 mils—including all values and sub-rangesthere-between. In some embodiments, the cellulosic layer 400 may form aveneer that is bonded to the substrate layer 200 by the adhesive layer300, whereby the cellulosic thickness t_(CL) may range from about 10mils to about 100 mils—including all values and sub-rangesthere-between. In other embodiments, the cellulosic layer 400 may formthe entirety of the body 100, whereby the cellulosic thickness t_(CL)may range from about 300 mils to about 3,000 mils—including all valuesand sub-ranges there-between.

The cellulosic layer 400 may be formed from a cellulosic material suchas wood, bamboo, and a combination thereof, and may be naturallyoccurring or engineered. Non-limiting examples of wood include cherry,maple, oak, walnut, pine, poplar, spruce, chestnut, mahogany, rosewood,teak, ash, hickory, beech, birch, cedar, fir, hemlock, basswood, alderwood, obeche wood, and combinations thereof. The cellulosic layer 400may comprise pores that are not only present within the body of thecellulosic layer 400 but also exposed on at least one of the uppercellulosic surface 411, lower cellulosic surface 412, and/or thecellulosic side surface 413. The porosity of the cellulosic layer 400will depend on the bamboo or type of wood selected as the material thatforms the cellulosic layer 400.

The benefit of using a cellulosic layer 400 is that the resultingbuilding panel 10 will exhibit authentic decorative features 30 of realwood and/or bamboo (e.g., wood grain, knots, burl, etc.) whileminimizing the overall thickness required for the building panel 10without necessitating artificial print layers. Artificial print layers,such as those on various papers or plastics, have been used as a way torecreate wood grain, knots, burl, etc., while minimizing layerthickness. Such print layers, however, are undesirable because of thelimited amount of variation the cellulosic pattern across a large numberof panels as compared to the same large number of panels that usecellulosic layers formed from real wood and/or bamboo. Stated otherwise,artificial print layers are not preferred because of the repetition inthe decorative pattern over large installation areas.

Although not limited to this embodiment, the coating 500 may be directlyatop the upper cellulosic surface 411, the lower cellulosic surface 412,and/or the cellulosic side surface 413 of the cellulosic layer 400. Thecoating 500 may be applied to the cellulosic layer 400 such that thelower coating surface 512 is in direct contact with the upper cellulosiclayer surface 412. In such embodiments, the lower coating surface 512may directly contact the upper cellulosic surface 411, such that theupper coating surface 511 forms at least a portion of the upper majorsurface 11 of the building panel 10.

Referring now to FIG. 2, according to some embodiments of the presentinvention the building panel 10 may include cellulosic layer 400 beingadhesively bonded to the substrate layer 200 by an adhesive layer 300.The combination of layers 200, 300, 400, 500 of the present inventioncreates a laminate structure having high lamination integrity in aceiling system under both standard conditions (i.e. daily operation ofan interior building environment) but also during exposure to theextreme heat and temperature that may result from a fire.

The substrate layer 200 may comprises an upper substrate surface 211 anda lower substrate surface 212 that is opposite the upper substratesurface 211. The substrate layer 200 may comprise a substrate sidesurface 213 that extends from the upper substrate surface 211 to thelower substrate surface 212 and forms a perimeter of the substrate layer200. The substrate side surface 213 may form a portion of the sidesurface 113 of the body 100. Stated otherwise, the side surface 113 ofthe body 100 may comprise the substrate side surface 213.

The substrate layer 200 may be formed from a metallic material, ceramicmaterial, or composite material. Non-limiting examples of metallicmaterial include aluminum, steel, and iron. In a preferred embodiment,the substrate layer 200 is formed from aluminum. The substrate layer 200may have a substrate thickness “t_(S)” ranging from about 20 mils toabout 100 mils—including all values and sub-ranges there-between. Thesubstrate thickness t_(S) may range from about 25 mils to about 80 mils.In a preferred embodiment, the substrate thickness t_(S) ranges fromabout 30 mils to about 65 mils—including all values and sub-rangesthere-between.

The adhesive layer 300 may comprises an upper adhesive surface 311 and alower adhesive surface 312 opposite the upper adhesive surface 311. Theadhesive layer 300 may comprise an adhesive side surface 313 thatextends from the upper adhesive surface 311 to the lower adhesivesurface 312 and forms a perimeter of the adhesive layer 300. Theadhesive side surface 313 may form a portion of the side surface 113 ofthe body 100. Stated otherwise, the side surface 113 of the body 100 maycomprise the adhesive side surface 213. The adhesive layer 300 may havean adhesive thickness “t_(A)” ranging from about 2 mils to about 20mils—including all values and sub-ranges there-between—as measured fromthe upper adhesive surface 311 to the lower adhesive surface 312. In apreferred embodiment, the adhesive thickness t_(A) ranges from about 5mils to about 15 mils—including all values and sub-ranges there-between.

According to embodiments where the building panel 10 has the laminatestructure, the overall panel thickness t_(P) of the building panel 10may be the summation of the substrate thickness t_(S), the adhesivethickness t_(A), the cellulosic layer thickness t_(CL), and the coatingthickness t_(C) as follows:

t _(P) =t _(S) +t _(A) +t _(CL) +t _(C)

The upper substrate surface 211 of the substrate layer 200 may directlycontact the lower adhesive surface 312 of the adhesive layer 300 and theupper adhesive surface 311 of the adhesive layer 300 may directlycontact the lower cellulosic surface 412 of the cellulosic layer 400such that the adhesive layer 300 adhesively bonds together thecellulosic layer 400 and the substrate layer 200. The lower coatingsurface 512 may directly contact the upper cellulosic surface 411, suchthat the upper coating surface 511 forms at least a portion of the uppermajor surface 11 of the building panel 10. In such embodiments, thelower substrate surface 212 may form at least a portion of the lowermajor surface 12 of the building panel 10.

The adhesive layer 300 may be formed from an adhesive composition thatis a hot-melt composition, water-based polyvinyl acetate adhesive, andcombinations thereof. According to the purposes of the presentinvention, the term “hot-melt adhesive composition” means a compositionhaving a melt viscosity that ranges from about 10,000 centipoise toabout 40,000 centipoise at a temperature of about 275° F.—including allvalues and sub-ranges there-between. The hot-melt adhesive compositionmay be solid at room temperature and be substantially free of solvent.The adhesive composition may comprise adhesive polymer in an amountranging from about 50 wt. % to about 100 wt. % based on the total weightof the adhesive composition—including all values and sub-rangesthere-between.

The adhesive polymer according to the present invention may be athermoplastic polymer. Non-limiting examples of the thermoplasticpolymer may include moisture cured polyester modified polyurethanepolymers. Such polyester modified polyurethanes may be formed byreacting organic diisocyanate with difunctional polyester polyol and lowmolecular weight diols (as chain-extending agents) at a non-limitingNCO:OH ratio of about 0.7:1 to about 1.3:1—including all sub-ranges andratios there-between.

Non-limiting examples of polyester polyol include di-functionalpolyester diols containing alcoholic hydroxyl groups. Suitable polyesterdiols are polyester having average molecular weights of from 800 to 5000and preferably from 2000 to 4000 produced from (i) dicarboxylic acidscontaining at least 6 carbon atoms, such as adipic acid, pimelic acid,suberic acid, azelaic acid and/or sebacic acid (preferably adipic acid,as the sole acid component) and (ii) alkane diols that may contain atleast 4 carbon atoms, such as, for example, 1,4-dihydroxy-butane,1,5-dihydroxypentane and/or 1,6-dihydroxy-hexane. Polycondensates ofw-hydroxyalkane-mono-carboxylic acids and the polymers of their lactonesare also suitable, although less preferred.

Low molecular weight diols suitable as chain-extending agents inaccordance with the present invention include, in particular, aliphaticdiols having average molecular weight of from 62 to 400 or mixturesthereof. Non-limiting examples of such diols include ethylene glycol,1,3-dihydroxy-propane, 1,4-dihydroxy-butane, 1,5-dihydroxypentane,1,6-dihydroxyhexane, and the like.

Non-limiting examples of suitable aromatic polyisocyanates include allisomers of toluylene-diisocyanate (TDI), naphthalene-1,5-diisocyanate,diphenylmethane-4,4′-diisocyanate (MDI),diphenylmethane-2,4′-diisocyanate and mixtures of4,4′-diphenylmethane-diisocyanate with the 2,4′ isomer or mixturesthereof with oligomers of higher functionality (so-called crude MDI),xylylene-diisocyanate (XDI), 4,4′-diphenyl-dimethylmethane-diisocyanate,di- and tetra-alkyl-diphenylmethane-diisocyanate,4,4′-dibenzyl-diisocyanate, 1,3-phenylene-diisocyanate and1,4-phenylene-diisocyanate. Examples of suitable cycloaliphaticpolyisocyanates are the hydrogenation products of the above-mentionedaromatic diisocyanates, such as 4,4′-dicyclohexylmethane-diisocyanate(H₁₂MDI), 1-isocyanatomethyl-3-isocyanato-1,5,5-trimethyl-cyclohexane(isophorone-diisocyanate, IPDI), cyclohexane-1,4-diisocyanate,hydrogenated xylylene-diisocyanate (H₆XDI),1-methyl-2,4-diisocyanato-cyclohexane, m- orp-tetramethylxylene-diisocyanate (m-TMXDI, p-TMXDI) and dimer-fatty aciddiisocyanate. Examples of aliphatic polyisocyanates aretetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate,hexane-1,6-diisocyanate (HDI), 1,6-diisocyanato-2,2,4-trimethylhexane,1,6-diisocyanato-2,4,4-trimethylhexane and 1,2-dodecane-diisocyanate(C₁₂DI).

The adhesive composition of the present invention may further compriseadditives selected from the group consisting of 2,2′-dimorpholinethylether catalyst, di(2,6-dimethylmorpholinoethyl)ether catalyst, adhesionpromoters, diluents, plasticizers, fillers, antioxidants pigments, UVabsorbers and combinations thereof. In other embodiments, the adhesivecomposition may further comprise a flame retardant. Non-limitingexamples of flame retardant may include ammonium hydroxide, magnesiumhydroxide, huntite, hydromagnesite, silica, polyphosphate, melaminecyanurate, chloride salts—such as sodium chloride, antimony oxide, andborates, such as calcium borate, magnesium borate, zinc borate, andcombinations thereof. The flame retardant may be present in the adhesivecomposition in an amount ranging from about 0 wt. % to about 50 wt. %based on the total weight of the adhesive composition—including allvalues and sub-ranged there-between.

The building panel 10 of FIG. 2 may be formed heating the adhesivecomposition to an application temperature ranging from about 245° F. toabout 330° F., and applying the adhesive composition to at least one ofthe upper substrate surface 211 or the lower cellulosic surface 412. Theadhesive composition may be applied by roll coating, spray coating, dipcoating, or the like. Within the open time of the adhesive (typically 30to 60 seconds), the upper substrate surface 211 is mated to the lowercellulosic surface 412 with the adhesive composition being presentthere-between, thereby bonding the upper substrate surface 211 to thelower cellulosic surface 412 via the adhesive composition. Pressure maythen be applied to at least one of the upper cellulosic surface 411 ofthe cellulosic layer 400 or the lower substrate surface 212 of thesubstrate layer 200 to ensure proper adhesive bonding.

Each sub-layer 540, 550, 560 may be individually applied by spray,roll-coating, dip coating, curtain coating, brushing, blade coating, orthe like. Specifically, the first sub-layer 540 may be applied to theupper cellulosic surface 411 of the cellulosic layer 400. The firstsub-layer 540 may then be optionally heated to a temperature rangingfrom about 68° F. to about 150° F. to partially or fully cure the firstsub-layer 540. The second sub-layer 550 may then be applied to the firstsub-layer supper surface upper surface 541. The second sub-layer 550 maythen be optionally heated to a temperature ranging from about 190° F. toabout 320° F. to partially or fully cure the second sub-layer 550. Thethird sub-layer 560 may then be applied to the second sub-layer uppersurface 551. The third sub-layer 560 may then be optionally heated to atemperature ranging from about 190° F. to about 320° F. to partially orfully cure the third sub-layer 560—thereby resulting in the laminatestructure of the present invention. The laminate structure may then beheated in an oven to fully cure the adhesive layer 300 and the coating500 for a fourth period of time.

According to the present invention, the coating 500 applied to thecellulosic layer 400 provides an aesthetically pleasing building panel10 such that the underlying body decorative features on the body 100 arevisible from the upper major surface 11 of the building panel 10 as thedecorative features 30, because the decorative coating 500 issubstantially clear. Furthermore, the inorganic composition of thecoating 500 helps provide an insulative heat-barrier to the cellulosiclayer 400, thereby helping prevent the cellulosic layer 400 fromigniting during a fire and propagating through the building panel 10.

The multi-layered coating 500 comprising the first sub-layer 540 mayalso at least partially seal the pores and the upper cellulosic surface411 such that at least a portion of the phosphoborate glass layer isformed at a distance separated from the upper cellulosic surface 411 ofthe cellulosic layer 400—further protecting the cellulosic layer 400from igniting in a fire. Additionally, the moisture sealant compositionof the third sub-layer 560 ensures that the glass-forming composition ofthe underlying sub-layers 540, 550 remains active for prolonged periodsof time in case an interior space catches fire years after initialinstallation.

Referring to FIG. 5, the building panel 10 of the present invention maybe a ceiling panel (as shown installed in the ceiling system of FIG. 5),a wall panel, or the like. The lower major surface 12 of the ceilingpanel 10 of the present invention may face the plenum space 3 of aninterior space of a ceiling system 1. The upper major surface 11 of theceiling panel 10 of the present invention may face the active space 2 ofan interior space of a ceiling system 1.

In non-exemplified embodiments, the present invention may include abuilding panel having an upper major surface opposite a lower majorsurface, the building panel comprising a cellulosic layer (also referredto as “cellulosic body” in this embodiment) and a coating. Thecellulosic body is self-supporting and comprises an upper cellulosicsurface and a lower cellulosic surface opposite the upper cellulosicbody. Non-limiting examples of a cellulosic body may include MDF board,wooden planks, or the like. The cellulosic body may have a cellulosicbody thickness as measured from the lower cellulosic surface to theupper cellulosic surface that ranges up to about 3 inches—including allvalues and sub-ranges there-between.

With the coating 500 being formed at drying temperatures as low as 150°F., the cellulosic body may at least partially retain pre-existingmoisture already contained within the cellulosic body. The surprisingbenefit of retaining the pre-existing moisture is that during exposureto high-heat, the retained moisture is converted to steam and driven outof the cellulosic body. As the steam escapes from the body 100, theglass layer formed from the coating 500 is pushed outward from the body100, thereby increasing the distance between the body 100 and thesurrounding flame or high-heat—thereby decreasing the likelihood thatthe body 100 ignites. Stated otherwise, it has been surprisinglydiscovered that the coatings 500 of the present invention furtherenhance fire repellency in the building panels 10 by allowing for dryingtemperatures below 212° F. under atmospheric conditions (at 1 atm).

The building panel 10 of such embodiments may have the coating 500applied to at least one of the upper cellulosic surface 411 or the lowercellulosic surface 412 of the cellulosic body 400. The coating 500comprises an upper coating surface 511 opposite a lower coating surface512, whereby the lower coating surface 512 of the coating 500 maydirectly contact the upper cellulosic surface 411 of the cellulosic body400. The coating 500 comprises at least the second sub-layer 550 andoptionally the first sub-layer 540 and/or the third sub-layer 560, aspreviously discussed. The upper major surface 11 of the building panel10 may comprise the upper coating surface 511 of the coating 500.According to some embodiments, the lower major surface 12 of thebuilding panel 10 may be uncoated, whereby the lower major surface 12 ofthe building panel 10 does not comprise the coating 500, but rather thelower cellulosic surface 412 or the lower substrate surface 212.

Referring now to FIGS. 6-8, a building panel 1010 and ceiling system1001 are illustrated in accordance with another embodiment of thepresent invention. The building panel 1010 is similar to the buildingpanel 10 except as described herein below. The description of thebuilding panel 10 above generally applies to the building panel 1010described below except with regard to the differences specifically notedbelow. A similar numbering scheme will be used for the building panel1010 as with the building panel 10 except that the 1000-series ofnumbers will be used. Additionally, the ceiling system 1001 is similarto the ceiling system 1 except as described herein below. Thedescription of the ceiling system 1 above generally applies to theceiling system 1001 described below except with regard to thedifferences specifically noted below. A similar numbering scheme will beused for the ceiling system 1001 as with the ceiling system 1 exceptthat the 1000-series of numbers will be used.

The coating 1500 of the present invention may be applied to one of thefirst major surface 1111, second major surface 1112, and/or side surface1113 of the body 1100. In a preferred embodiment, the coating 1500 isapplied to each of the first major surface 1111, the second majorsurface 1112, and the side surface 1113 of the body 1100 such that thecoating 1500 encapsulates the body 1100. Stated otherwise, the coating1500 may form a continuous barrier that substantially surrounds theentire body 1100.

Although not pictured, the coating 1500 of this embodiment comprises thesecond sub-layer 550, and may further comprise each of the firstsub-layer 540 and/or third sub-layer 560, as previously discussed withrespect to FIGS. 2-4.

In these embodiments, the body 1100 may formed entirely from thecellulosic body 400 or the substrate layer 200. The body 1100 mayalternatively be formed from the laminate structure. According to theembodiments where the body 1100 is formed entirely from the cellulosicbody 400, the overall panel thickness t_(P) may be the summation ofcellulosic body thickness t_(CL), and the coating thickness t_(C) asfollows:

t _(P) =t _(CL) +[n×t _(C)]

whereby the “n” refers to the number of major surfaces of the body 1100coated with the coating 1500. In this embodiment, the first and secondmajor surfaces 1111, 1112 of the body 1100 are coated and n=2. In suchembodiments, the panel thickness t_(P) may range from about 500 mils toabout 2,000 mils—including all values and sub-ranges there-between.

According to the embodiments where the body 1100 is formed entirely fromthe substrate layer 200, the overall panel thickness t_(P) may be thesummation of substrate layer thickness t_(S), and the coating thicknesst_(C) as follows:

t _(P) =t _(S) +[n×t _(C)]

whereby the “n” refers to the number of major surfaces of the body 1100coated with the coating 1500. In this embodiment, the first and secondmajor surfaces 1111, 1112 of the body 1100 are coated and n=2. In suchembodiments, the panel thickness t_(P) may range from about 100 mils toabout 600 mils—including all values and sub-ranges there-between.

Referring now to FIG. 8, the building panel 1010 of these embodimentsmay be installed into a ceiling system 1001 comprising a support 1005that includes a first support member 1005 a and a second support member1005 b. The first and second support members 1005 a, 1005 b may bearranged in an intersecting pattern to form a support grid. A pluralityof the building panels 1010 may be arranged in an array and attached tothe support grid such that the upper major surface of one building panel1010 faces the lower major surface of a second building panel 1010 thatis adjacent to the first building panel 1010. The plurality of thebuilding panels 1010 may also be arranged and attached to the supportgrid such that the plurality of building panels 1010 comprises a firstside 1041 opposite a second side 1042, whereby the firs side 1041 facesthe plenum 1003 and the second side 1042 faces the room environment1002—the first and second sides 1041, 1042 comprises the side surface1013 of the building panels 1010.

The following examples are prepared in accordance with the presentinvention. The present invention is not limited to the examplesdescribed herein.

EXAMPLES Experiment 1

A first set of experiments was performed by coating a number ofcellulosic bodies with the inorganic composition of the presentinvention in the wet-state. Specifically, a major surface of eachcellulosic body had the dimensions of 3.75″×29.875″, which were coatedby the coating of the present invention. Each coated body was then driedat a temperature ranging between 200° F. to 275° F. Each specimen wasthen positioned above a Bunsen burner angled at 30°, whereby the coatedmajor surface faces the flame from the Bunsen burner. Each surface wasexposure for a set predetermined amount of time, after which the amountof flame spread on each specimen was measured and assigned a value—thelower the Flame Spread Rating (“FSR”) value, the better the coating wasat imparting flame-retardancy to the underlying substrate.

Additionally, using a correlation between measured FSR values and knownflame spread and smoke index values generated by an ASTM E-84 test, theFSR values were able to be correlated to Class A, B, or C flameretardancy. Specifically, FSR values <25 translate to high probabilityof a Class A fire rating. FSR values between 25 and 40 translate to amoderate probability of Class A fire rating. FSR values >40 translate toa low probability of Class A fire rating.

TABLE 1 Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. 1 2 3 4 5 67 8 9 10 11 12 13 Component (wt. %) 14A 14B 14C 23B 32A 50D 50E 103B103C 107F 115A 115C 131B Water 77.3 71.3 67.2 68.6 53.9 68.4 68.1 65.870.4 63.7 64.7 66.0 45.1 H₃PO₄ 13.6 17.2 20.4 20.9 32.3 20.7 20.7 23.017.0 21.3 21.5 22.0 35.7 HNO₃ — — — — — 0.2 0.2 — — — — — — B₂O₃ 1.8 1.61.5 — 1.6 0.3 0.3 — — — — — 2.0 2ZnO•3 B₂O₃•3.5H₂O — — — — — — — 3.3 3.22.8 2.9 4.4 — CaCO₃ — — — — — — 0.3 — — 0.6 0.6 0.6 0.9 Al₂(CO₃)₃ — — —— — — — — — 2.8 — — 4.8 Li₂CO₃ — — — 3.1 6.1 — — — — — — — — MgCO₃ 7.39.9 10.9 7.4 6.1 10.4 10.4 6.6 6.5 5.7 8.6 4.7 7.6 Fumed SiO₂ — — — — —— — 1.3 — 1.4 — 0.6 1.0 Hydroxyethylecellulose — — — — — — — — 2.9 — — —— Triethanolamine — — — — — — — — — 1.7 1.7 1.7 2.9 Total 100 100 100100 100 100 100 100 100 100 100 100 100 Total Amount of 0.0 0.0 0.0 0.00.0 0.2 0.2 0.0 2.9 1.7 1.7 1.7 2.9 Organic pH 3.5 3.83 3.47 3.90 2.262.87 2.65 2.51 2.51 2.46 2.50 2.50 2.10

With the formulations set forth in Table 1, the following heat and flameperformance are provided below in Table 2.

TABLE 2 Ex. 7 Ex. 11 Ex. 12 Ex. 13 Organic Sealer Wet Density (g/ml)1.23 1.24 — 1.29 1.02 Wet Thickness (mil) 0.2 0.35 0.35 0.5 1.6 DryThickness (mil) 0.05 0.12 0.12 0.28 0.50 Total Amount of 0.2 1.7 1.7 2.9100% Organic (Dry) FSR 37 87 87 29 Very Poor Optical Clarity — 78% —100% 108% Gloss (60°) — 59.3 — 51.5 25.0

As shown in Table 2, the coating comprising the inorganic composition ofthe present invention comprising minor amounts of organic composition(i.e., <1.0 wt. % based on total dry-weight) resulted in superior FSR of37, as compared to Examples 11 and 12 having greater amounts of organiccomposition (>4 wt. %), which resulted in an FSR of 87—even at smallapplication amounts (dry thicknesses as low as 0.05 mils). Additionally,each inorganic coating compositions of the present invention allows forsuperior flame resistance while still maintaining high visual clarity(i.e., >70%).

Furthermore, as demonstrated by Example 13, it has been surprisinglydiscovered that greater amounts of organic composition (i.e., about 5wt. % based on the dry-weight) may be added to the inorganic compositionwhile still maintaining desirable FSR performance when the inorganiccomposition further comprises aluminum carbonate Al₂(CO₃)₃.

Furthermore, while the gloss value of the present invention may increaserelative to the organic coating, such values still remain within anacceptable range of increase of such values compared to the organiccoating. More importantly, the coatings of the present invention providecoatings having superior changes in optical clarity. According to thepresent invention, the percent change in optical clarity is a measure ofcolor values before and after application of the coating, whereby whenthe color values improve (i.e., increase) there is a correspondingincrease in optical clarity as the appearance of the underlyingsubstrate has become more apparent. Thus, achieving >100% opticalclarity is possible as it represents an improvement in discernible colorof the underlying substrate through the respective coating.

Experiment 2

A second set of experiments was performed by coating a number ofcellulosic bodies with a multi-layered coating comprising the inorganiccomposition of the present invention in the wet-state. Each buildingpanel was then subjected to color and gloss measurements as well aspencil hardness tests. The results are provided below in Table 3.

TABLE 3 Phosphate Untreated Coating System Control Wood Base CoatOrganic Organic None Intermediate Coat Ex. 13 Flame-Retardant NoneOrganic Topcoat Ex. 11 Flame-Retardant None Organic Gloss (60°) 19.4 213.2 Color L 65.4 80.4 71.95 a 7.16 2.7 3.85 b 23.92 23 20.22 PencilHardness 8H 2H None

As demonstrated by Table 3, the multi-layered coating comprising theinorganic composition of the present invention (referred to as“Phosphate Coating System”) demonstrates desirable color and glossperformance when compared to the flame-retardant organic coating.Specifically, the Phosphate Coating System exhibits slight darkening (asmeasured by the decreased “L” value) as well as an increase in red color(as measured by the increase in “a” value”) however, such values remainwithin an acceptable range of optical performance—especially whenconsidering the drastic improvement in flame retardancy of the PhosphateCoating System compared to the Flame-Retardant Organic coating—asdemonstrated in Experiment 3.

Experiment 3

A third experiment was performed by subjecting each of the panels ofExperiment 2 to the FSR test. The results are provided below in Table 4.

TABLE 4 Phosphate Untreated Coating System Control Wood Base CoatOrganic Coating Organic Coating None Intermediate Coat Ex. 13Flame-Retardant None Organic Topcoat Ex. 11 Flame-Retardant None OrganicFSR 29 90-97 99

As demonstrated by Table 4, the multi-layered coating of the presentinvention resulted in superior FSR performance as compared to theorganic based multi-layered coating of the Control.

1. A flame-retardant building panel comprising: a body having a firstmajor surface opposite a second major surface; an inorganic coating atopthe first major surface, the inorganic coating being opticallytransparent and flame retardant and comprising a blend of a boratecompound and a phosphate compound; and wherein the inorganic flameretardant coating is substantially transparent such that the first majorsurface of the body is visible through the inorganic coating.
 2. Theflame-retardant building panel according to claim 1, wherein the firstmajor surface of the body is formed from a material selected from thegroup consisting of wood, metal, or non-woven scrim. 3.-5. (canceled) 6.The flame-retardant building panel according to claim 1, wherein theinorganic coating has a thickness ranging from about 0.3 mils to about3.0 mils.
 7. The flame-retardant building panel according to claim 1,wherein the borate compound is selected from the group consisting ofboron trioxide, zinc borate, and combinations thereof.
 8. Theflame-retardant building panel according to claim 1, wherein thephosphate compound is selected from the group consisting of phosphoricacid, pyrophosphoric acid, polyphosphoric acid, aluminum tris(dihydrogen phosphate), sodium phosphate, potassium phosphate, andcombinations thereof.
 9. The flame-retardant building panel according toclaim 1, wherein the borate compound and the phosphate compound arepresent in a weight ratio ranging from about 1:1 to about 1:1000. 10.The flame-retardant building panel according to claim 1, wherein thebody is encapsulated by the inorganic coating.
 11. The flame-retardantbuilding panel according to claim 10, wherein the inorganic coatingfurther comprises filler selected from the group consisting of calciumcarbonate, aluminum carbonate, lithium carbonate, magnesium carbonate,silica, fumed silica, and combinations thereof.
 12. The flame-retardantbuilding panel according to claim 1, wherein the inorganic coatingfurther comprises an organic component in an amount ranging from anon-zero value up to about 5 wt. %
 13. The flame-retardant buildingpanel according to claim 12, wherein the organic component is selectedfrom the groups consisting of wetting agent, hydroxyethylcellulose,triethanolamine, and combinations thereof.
 14. (canceled)
 15. Aflame-retardant building panel comprising: a body having a first majorsurface opposite a second major surface; an inorganic coating applied tothe first major surface, the inorganic coating formed from a compositioncomprising a blend of a borate compound and a phosphate compound; andwherein the composition has a maximum pH of
 5. 16. (canceled)
 17. Theflame-retardant building panel according to claim 15, wherein theinorganic coating is glass-forming. 18.-20. (canceled)
 21. Theflame-retardant building panel according to claim 15, wherein the boratecompound is selected from the group consisting of boron trioxide, zincborate, and combinations thereof.
 22. The flame-retardant building panelaccording to claim 15, wherein the phosphate compound is selected fromthe group consisting of phosphoric acid, pyrophosphoric acid,polyphosphoric acid, aluminum tris (dihydrogen phosphate), sodiumphosphate, potassium phosphate, and combinations thereof.
 23. Theflame-retardant building panel according to claim 15, wherein the boratecompound and the phosphate compound are present in a weight ratioranging from about 1:1 to about 1:1000. 24.-28. (canceled)
 29. Theflame-retardant building panel according to claim 15, wherein theinorganic flame retardant coating is substantially transparent such thatthe first major surface of the body is visible through the inorganiccoating. 30.-40. (canceled)
 41. A flame-retardant building panelcomprising: a body having a first major surface opposite a second majorsurface; a top coat comprising a first sub-layer and a second sub-layer,the first sub-layer atop the first major surface of the body and thesecond sub-layer atop the first sub-layer; and wherein the firstsub-layer is an organic coating and the second sub-layer is an inorganiccoating comprising a blend of a borate compound and a phosphatecompound.
 42. (canceled)
 43. The flame-retardant building panelaccording to claim 41, wherein top coat is optically transparent suchthat the first major surface of the body is visible through the topcoat.
 44. The flame-retardant building panel according to claim 41,wherein the inorganic coating is formed from a composition comprisingthe blend of the borate compound and the phosphate compound, wherein thecomposition has a maximum pH of about
 5. 45. The flame-retardantbuilding panel according to claim 41, wherein the inorganic coatingcomprises up to about 5 wt. % of organic components based on the totalweight of the inorganic coating. 46.-61. (canceled)